Green luminescent materials

1. An organic electronic device comprising a first electrical contact, a second electrical contact and a photoactive layer therebetween, the photoactive layer comprising a green luminescent material having Formula II, or a mixture of compounds having Formula I and Formula II

wherein:

R 1 and R 2 are the same or different and are selected from the group consisting of hydrogen, alkoxy, tertiary alkyl, and cycloalkyl,

R 3 and R 4 are the same or different and are selected from the group consisting of fluorine, aryl, and alkyl,

wherein:

R 1 and R 2 are the same or different and are selected from the group consisting of alkoxy, tertiary alkyl, and cycloalkyl,

R 3 and R 4 are the same or different and are selected from the group consisting of fluorine, aryl, and alkyl.

2. The device of claim 1 , wherein, in Formula I, at least one of R 1 and R 2 is not hydrogen.

3. The device of claim 1 , wherein at least one of R 1 and R 2 is an alkoxy group selected from the group consisting of methoxy and ethoxy.

4. The device of claim 1 , wherein at least one of R 1 and R 2 is a tertiary alkyl group selected from the group consisting of t-butyl and neopentyl.

5. The device of claim 1 , wherein at least one of R 1 and R 2 is a cycloalkyl selected from the group consisting of cyclohexyl, 1-methylcyclohexyl, and 1-adamantyl.

6. The device of claim 1 , wherein the luminescent material of Formula I and II are selected from the group consisting of compounds G1 through G12, for the respective Formula:

Com-

pound

Formula

R 1

R 2

R 3

R 4

G1

I

H

H

i-propyl

t-butyl

G2

I

t-butyl

H

i-propyl

t-butyl

G3

I

t-butyl

t-butyl

i-propyl

t-butyl

G4

I

1-

1-

i-propyl

t-butyl

methylcyclohexyl

methyl-

cyclohexyl

G5

II

1-

1-

i-propyl

t-butyl

methylcyclohexyl

methyl-

cyclohexyl

G6

I

methoxy

methoxy

i-propyl

t-butyl

G7

I

1-adamantyl

1-adamantyl

i-propyl

t-butyl

G8

II

1-adamantyl

1-adamantyl

i-propyl

t-butyl

G9

I

t-butyl

t-butyl

F

F

G10

I

1-adamantyl

1-adamantyl

phenyl

phenyl

G11

I

1-adamantyl

1-adamantyl

t-butyl

3-biphenyl

G12

I

1-adamantyl

1-adamantyl

t-butyl

phenyl.

7. The device of claim 1 , wherein the photoactive layer further comprises a host material.

8. The device of claim 7 wherein the host material comprises at least one diarylanthracene.

9. The device of claim 8 wherein the diarylanthracene has the formula:

where:

A 1 and A 2 are the same or different at each occurrence and are selected from the group consisting of H, an aromatic group, and an alkenyl group, or A may represent one or more fused aromatic rings;

p and q are the same or different and are an integer from 1-3.

10. The device of claim 9 wherein at least one of A 1 and A 2 comprises a naphthyl group.

11. The device of claim 10 wherein the host is selected from the group consisting of

and combinations thereof.

12. The device of claim 1 , wherein R 1 and R 2 are the same.

13. The device of claim 1 , wherein the compounds having Formula I and Formula II are isomers.